The high court is widely expected to strike down Chicago’s 28-year-old handgun ban this summer, following the court’s 2008 decision to overturn a similar ordinance in Washington, D.C. Suburban gun store owners anticipate the court’s next move will uncork pent-up demand for firearms within Chicago city limits.

Nixing the city’s ban “is going to open up business to thousands and thousands of households, and that could mean thousands and thousands in sales,” says Fred Lutger, owner of Freddie Bear Sports, the outdoor-sports store he’s operated in south suburban Tinley Park for 30 years.

Like other gun retailers, Mr. Lutger has seen sales accelerate since just before Mr. Obama’s election, as gun enthusiasts rushed to buy firearms out of fear that the new president would enact tougher gun-control laws.

Mr. Lutger’s sales have climbed 50% in that period. Noel Incavo, co-owner of Midwest Sporting Goods in west suburban Lyons, has seen a 30% jump. Neither expects a drop-off; it seems the fear of a gun ban can have the same effect on sales as a ban’s demise.

Anytime you talk about gun legislation, pro or con, we always see some kind of spike in sales,” Mr. Incavo says. “When the D.C. case was decided, we had a spike in sales because people were anticipating that Chicago was going to be next. This is a lot closer to home.”